HomeMy WebLinkAboutWRN WTP Exp_HEC-RAS Model Submission_0.4.30.258250 Haverstick Road, Suite 285
Indianapolis, Indiana 46240
www.tylin.com
MEMORANDUM
DATE: April 29, 2025
TO: Indiana DNR and City of Carmel
C: Citizens Energy Group, Arcadis
FROM: TYLin
SUBJECT: WRN WTP Expansion Floodplain Model
Introduction
Citizens Energy Group White River North (WRN) Water Treatment Plant (WTP) is located in Carmel,
Indiana on the White River near the 116th Street bridge. Existing plant capacity is 34 million gallons per
day (MGD). The site lies within the 100-year floodplain with portions of the site within the 100-year
floodway. The area north of Sedimentation Basin No. 2 and the existing earthen solids lagoon are
currently within the Federal Emergency Management Agency (FEMA) Special Hazard Area (SFHA)
Floodway in Zone AE. The proposed site plan with the floodway and floodplain boundaries is attached in
Appendix A.
Water Treatment Plant Expansion
The WRN WTP treatment capacity will be expanded from 34 MGD to 59 MGD. As part of the expansion,
the area north of Sedimentation Basin No. 2 will become the location of proposed Sedimentation Basins
No. 3 and 4 and a new filter building. A portion of the existing Residuals Management system will be
converted to a mechanical dewatering system including two new structures to house belt filter presses
and gravity thickeners. A new below-grade chlorine contact tank will be constructed north of the existing
chlorine contact tank. One WRN WTP Expansion design objective was to ensure that the expansion does
not increase the risk of flooding. To substantiate this objective, a hydraulic study was performed to
demonstrate a No-Rise to the Base Flood Elevation.
Hydraulic Study
The model for this analysis was a modified model from the Hydro Model ID 4763 model dated 8/8/2012
with a Reach ID of 180570100013 obtained from Indiana Department of Natural Resources (IDNR)
Hydrology and Hydraulics Model Library. The model encompasses an area of the West Fork White River
that includes the WRN WTP. The model submitted with this report is based on modeling approved by the
Indiana Department of Natural Resources for application numbers FW-26,725, which includes previous
projects FW-20,451, FW-20,770, FW-22,170, FW-24,049, FW-25,018, and FW-25,815.
| 2
The existing discharge of 45,000 cfs within the study area was not modified from the submitted FW-
26,725 model.
‒ The following models were ran and the results are attached.Duplicate Effective Model - Base model
submitted under FW-26,725. This was a re-run with no modifications other than using HEC-RAS version
6.5.
‒ Corrected Effective Model (Existing) – The corrected effective model was developed to incorporate the
improved topography and bathymetry, which was in place at the time of the of the effective model. To
accomplish this, new cross sections at locations of proposed work were sampled from the existing
surface to model. New cross sections used bathymetry, WRN WTP site survey, and regional LiDAR. The
bathymetry, survey and LiDAR information was in NAVD and was converted to NGVD to be consistent
with the model. Note that the Corrected Effective Model also acts as the Existing Model. An Existing
Model can be different from a Corrected Effective Model if there are modifications within the
floodplain since the date of the effective model but prior to this project. In the case of this location,
there have been no significant changes since the FW-26,725.Thus, that the Corrected Effective Model
also represents the Existing Model because there are no additions that are not represented by updated
survey additional cross-sections
‒ Proposed Conditions Model (Proposed) – Proposed buildings and site grading were added to new
cross sections within the Corrected Effective Model.
Five cross-sections were added to the Corrected Effective model at the locations of the proposed
improvements and the hydraulic shadows on the upstream and downstream side of the residual
management area. A sixth cross-section (Existing Main Building) was added downstream of the proposed
improvements to better reflect existing conditions of the grade between FEMA FIS XS F and the Filter
Building cross-section as there was an abrupt change in area. The abrupt change in area was reduced by
the addition of the intermediate cross section which includes no proposed changes in grade.
‒ RM 254.53 – WRN WTP – Upstream Hydraulic Shadow
‒ RM 254.49 – WTN WTP – New Dewatering Building
‒ RM 254.44 – WRN WTP – New Residual Mgmt and Dewatering Building
‒ RM 254.40 – WRN WTP – Downstream Hydraulic Shadow
‒ RM 254.33 – WRN WTP – Filter Building
‒ RM 254.28 – WRN WTP – Existing Settling Basin
For this analysis, the existing model reach was evaluated between 254.28 and 254.53.
The most restrictive cross section as part of the project is the RM 254.33 – WRN WTP – Filter Building
cross section. The Corrected Effective (Existing) Model that the Base Flood Elevation (BFE) at the Filter
Building Cross Section is 745.95’ NGVD (745.67’ NAVD) feet, although, the BFE varies along the length of
the site. The proposed site plan with proposed contours and building finished floor elevations and most
restrictive cross section are attached in Appendix A. The following subsections discuss the development
of the preliminary hydraulic model to demonstrate the feasibility of creating a “no rise” development for
this plan.
Duplicate Effective Model
The Duplicate Effective model is the Base model submitted under FW-26,725 re-run in HEC-RAS version
6.5. The re-run results do not show any significant changes from FW-26,725.
| 3
Corrected Effective Model
The Corrected Effective model was modified from the 2024 hydraulic study to better reflect the site
conditions. Some of the improvements included:
‒ incorporating more complete data across the full floodplain width,
‒ making corrections to the surface terrain model, and
‒ adding ineffective flow areas for the intervening high ground.
The ineffective flow area was one of the more significant changes to the model and provided a simulation
that was more closely related to what would be expected at the site. An ineffective flow area is defined as
an area where the velocity is assumed to be zero, often in backwater areas. The WRN WTP is found on
intervening high ground that does not allow the White River flow through. That intervening high ground
creates a backwater where it is reasonable to assume near-zero velocities. Additionally, there are lagoons
that will not be modified in between the river and the high ground that have been marked as ineffective.
For example in cross section 254.33, stations 1138.49’-1311’ mark the lagoon.
We used a 1:1 contraction to project the effects of the downstream intervening high ground on the
upstream sections. This is reflected in the following sections:
· RM 254.4 – Downstream Hydraulic Shadow
· RM 254.44 – Residual Management and Dewatering Building
· RM 254.49 – Residual Management, and RM 254.53 – Upstream Hydraulic Shadow.
In RM 254.33 – Filter Building, areas where the intervening high ground is higher than the BFE was
modeled as a levee, as the lower grade is protected by intervening high ground. While modeling shows a
levee, this is not a regulatory levee.
Existing Model
The existing model is the same as the corrected effective model.
Proposed Conditions Model
The Proposed Conditions model is the Corrected Effective model with new features from this application.
New buildings will be constructed in the floodplain as part of the WRN WTP Expansion project including
the Residual Management Building, Dewatering Building, Filter Building, Sedimentation Basins, and
chlorine contact tank. The Proposed Conditions model includes the new buildings and proposed grading.
The proposed Residual Management Building and Dewatering Building are structures that could influence
the conveyance of flows. Hydraulic shadows were assumed immediately upstream and downstream of the
structures and modeled at a 1:1 ratio upstream and downstream of the extents of the structures.
Model Results Comparison
The Proposed Conditions model results were compared with the Corrected Effective model results. See
attached Hydraulic Modeling Checklist in Appendix B and Project Evaluation Table in Appendix C for the
model comparison at the cross sections within the hydraulic reach. The checkRAS output is attached in
Appendix D. The comparative cross section plots are located in Appendix E.
APPENDIX A
Plan View and Most Restrictive Cross Section
Citizens Energy Group
White River North Water Treatment Plant Expansion
WRN WTP Expansion Floodplain Model
0+
0
0
1+
0
0
2+0
0
3+
0
0
4+
0
0
5+
0
0
6+007+008+009+0010+0011+0012+0013+0014+00
15+
0
0
16+00
17+00
18+00
19+00
20+00
21+00
22+00
23+00
24+00
25+
0
0
26+
0
0
7
4
0
75
0
7
4
5
740
7
3
0
7
2
5
7
2
5
7
3
0
7
3
5
73
5
73
5
74
0
74
5
74574574
0
74
0
7
4
0
7
4
0
74
5
745
7
4
0
74
0
74
0
740
745
745
74
5
74
5
74
0
740
73
5
73
5
7
3
5
7
3
0
7
2
5
72
0
7
2
0
7
2
0
7
2
5
73
0
73
5
7
4
0
7
4
5
7
5
0
7
5
5
750745740
73
5
73
0
72
5
7
2
0
72
0
72
5
73
0
73
5
73
5
73
5
73
5
740
74
574
5
74
5
7
4
5
74
5
74
5
745
740
74
0
74
0
74
5
74
5
74
0
74
0
745
745
74
5
745
745
7
4
0
735
7
3
5
735
735 73
0
72
5
720
720
725
73
0
735
74
0
745
75
0
76
0
75
5
75
0
74
5
74
0
73
5
73
0
72
5
72
5
730
735
735
735
73
5
7
3
5
73
5
73
5
74
0
745
750
74
5
74575
0
750
7
4
5
7
4
5
75
0
74
5
74
0
7
3
5
73
5
73
5
735
735
735
73
0
72
5
72
5
73
0
735
74
0
74
5
750
7
5
5
73
5
7
3
5
PROP
O
S
E
D
CHLO
R
I
N
E
CONT
A
C
T
BASIN
PROP
O
S
E
D
FILTE
R
BUILD
I
N
G
SETT
L
I
N
G
B
A
S
I
N
M
A
I
N
T
.
B
L
D
G
RE
S
I
D
U
A
L
MA
N
A
G
E
M
E
N
T
DE
W
A
T
E
R
I
N
G
BU
I
L
D
I
N
G
PAC S
I
L
O
PAC S
I
L
O
T:
\
O
\
G
H
-
I
N
D
\
L
\
P
R
O
J
E
C
T
S
\
0
2
5
9
_
C
E
G
\
3
0
3
5
.
0
0
0
0
3
0
3
.
0
0
2
_
W
R
N
E
X
P
-
F
L
O
O
D
P
L
A
I
N
M
O
D
E
L
I
N
G
S
U
P
P
O
R
T
\
0
4
-
C
A
D
_
B
I
M
_
G
I
S
\
C
I
V
I
L
3
D
\
F
I
G
\
0
3
0
3
R
0
1
20
2
5
/
0
4
/
3
0
11
:
2
7
A
M
MA
T
T
H
E
W
R
O
D
E
N
B
E
C
K
CITIZENS ENERGY GROUP
WRN EXPANSION
FIGURE 1
OVERALL SITE PLAN
SCALE: 1"=200'
100 0 100 200 FT
1"=200'
WH
I
T
E
R
I
V
E
R
FL
O
W
E 1
1
6
T
H
S
T
E 1
2
2
N
D
S
T
RM 254.40
RM 254.44
RM 254.49
RM 254.53
RM 254.33
RM 254.28
100 YEAR FLOODPLAIN
100 YEAR FLOODPLAIN
FLOODWAY
FLOODWAY
1:1 CONTRACTION
1:1 CONTRACTION
WA
T
E
R
F
L
O
W
DI
R
E
C
T
I
O
N
WA
T
E
R
F
L
O
W
DI
R
E
C
T
I
O
N
INEFFECTIVE TO 748 ELEVATION
DUE TO INTERVENING HIGH GROUND
INEFFECTIVE TO 746 ELEVATION
DUE TO INTERVENING HIGH GROUND
INEFFECTIVE TO 746 ELEVATION
DUE TO INTERVENING HIGH GROUND
INEFFECTIVE TO 746 ELEVATION
DUE TO INTERVENING HIGH GROUND
1
1
1
1
EL 710 TO EL 770
710
715
720
725
730
735
740
745
750
755
760
765
770
710
715
720
725
730
735
740
745
750
755
760
765
770
0+00 1+00 2+00 3+00 4+00 5+00 6+00 7+00 8+00 9+00 10+00 11+00 12+00 13+00 14+00 15+00 16+00 17+00 18+00 19+00 20+00 21+00 22+00
T:
\
O
\
G
H
-
I
N
D
\
L
\
P
R
O
J
E
C
T
S
\
0
2
5
9
_
C
E
G
\
3
0
3
5
.
0
0
0
0
3
0
3
.
0
0
2
_
W
R
N
E
X
P
-
F
L
O
O
D
P
L
A
I
N
M
O
D
E
L
I
N
G
S
U
P
P
O
R
T
\
0
4
-
C
A
D
_
B
I
M
_
G
I
S
\
C
I
V
I
L
3
D
\
F
I
G
\
0
3
0
3
R
0
1
20
2
5
/
0
4
/
2
3
11
:
4
6
A
M
MA
T
T
H
E
W
R
O
D
E
N
B
E
C
K
FIGURE 2
PROFILE
SCALE: 1"=200' (H), 1"=20' (V)
10 0 FT20
1"=20'
100 0 100 200 FT
1"=200'HORIZ
VERT
10
BASE FLOOD EL 745.54
EXISTING GRADE
VERTICAL DATUM
ORIGINATING BENCHMARK:
BENCHMARK NAME: HCBR 141 PER HAMILTON CO. SURVEYOR'S OFFICE VERTICAL CONTROL SHEET
A STANDARD HAMILTON COUNTY VERTICAL GEODETIC CONTROL DISK; STATION NAME HCBR 141 SET IN
THE SOUTH END OF THE WEST HANDRAIL OF RIVER ROAD BRIDGE OVER VESTAL DITCH.
ELEVATION = 754.38 (NAVD 1988)
HORIZONTAL DATUM
NAD 83 INDIANA STATE PLANES, EAST ZONE, US FOOT
CITIZENS ENERGY GROUP
WRN EXPANSION
EXISTING AREA BELOW
BFE PROTECTED BY
INTERVENING HIGH GROUND
PROPOSED GRADE
AND STRUCTURES
APPENDIX B
Hydraulic Modeling Checklist
Citizens Energy Group
White River North Water Treatment Plant Expansion
WRN WTP Expansion Floodplain Model
APPENDIX C
Project Evaluation Table
Citizens Energy Group
White River North Water Treatment Plant Expansion
WRN WTP Expansion Floodplain Model
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10) (11)
Model Cross Section
Station Location Description
Duplicate Effective
Model (Ft., NGVD)
(WRNDupEff)
Corrected
Effective Model
(Ft., NGVD)
(WRNExisting)
Existing
Conditions Model
(Ft., NGVD)2
(WRNExisting)
Proposed
Conditions Model
(Ft., NGVD)
(WRNProposed)
Cumulative
Impacts w/o
Project (ft)
(6)-(5)
Cumulative
Impacts Project
(ft)
(7)-(5)
Project Impacts
(ft)
(7)-(6)
251.79 D/S end of study reach - 741.56 741.6 741.6 741.6 0 0 0 -
254.18 FEMA FIS XS F 744.81 745.56 745.78 745.78 745.78 0 0 0 -
254.28 WRN WTP- Existing Settling Basin - _ 745.81 745.81 745.81 0 0 0 -
254.33 WRN WTP - New Filter Building - _ 745.95 745.95 745.95 0 0 0
Proposed Work; Existing area is
protected by intervening high
ground
254.4 WRN WTP - Downstream Hydraulic Shadow - _ 746.08 746.08 746.08 0 0 0 Proposed Work
254.44 WRN WTP - New Residual Mgmt and Dewatering Building - _ 746.15 746.15 746.15 0 0 0 Proposed Work
254.49 WRN WTP - New Residual Mgmt - _ 746.24 746.24 746.24 0 0 0 Proposed Work
254.53 WRN WTP - Upstream Hydraulic Shadow - _ 746.29 746.29 746.29 0 0 0 Proposed Work
254.8 FEMA FIS XS G 745.71 746.7 747.6 747.6 747.54 0 -0.06 -0.06 -
255.9 U/S end of study reach - 748.59 749.31 749.31 749.27 0 -0.04 -0.04 -
Notes:
1 FIS listed in NAVD; Converted to NGVD by adding 0.41'.
2 Existing Conditions Model was not run. Existing conditions model results are same as Corrected Effective Model results.
Project Evaluation Table
White River North Water Treatment Plant Expansion
Location Description Modeling Results ComparisonsPublished or
Effective Data (Ft,
NGVD)1
(Based on FIS
Table or Profile)
Notes
APPENDIX D
CheckRAS Output
Citizens Energy Group
White River North Water Treatment Plant Expansion
WRN WTP Expansion Floodplain Model
cHECk-RAS Report
HEC-RAS Project:wrnexisting.prj
Plan File:wrnexisting.p06
Geometry File:wrnexisting.g43
Flow File:wrnexisting.f03
Report Date:4/29/2025
Message ID Message Cross sections affected Comments
MP SW 01DK The name of the stream is
($streamname$).
The flow regime is subcritical or
mixed flow.
Starting water-surface elevations
are computed from Known WSELs as
the downstream boundary
condition.
Provide backup information on
Known water-surface elevations or
use same energy slope for all the
profiles as the starting boundary
condition and rerun the plan.
NT RS 02BDC This is the Downstream Bridge
Section (BRD). The channel n
value of $chldn$ for the
downstream internal bridge
opening section is equal to or
larger than the channel n value
of $chl2$ at Section 2. Usually,
the channel "n" value of the
bridge opening section represents
the area below the bridge deck
and is less than the channel "n"
value of Section 2. The "n" value
for Section 2 represents the
natural valley channel section
roughness for the reach between
Section 3 and Section 4. Please
change the "n" value of the
internal bridge opening section
or provide supporting information
for the use of the higher "n"
value.
253.335(Bridge-DN)
NT RS 02BUC This is the Upstream Bridge
Section (BRU). The channel n
value of $chlup$ for the upstream
internal bridge opening section
is equal to or larger than the
channel n value of $chl3$ at
Section 3. Usually, the channel
"n" value of the bridge opening
section represents the area below
the bridge deck and is less than
the channel "n" value of Section
3.
The "n" value for Section 3
represents the natural valley
channel section roughness for the
reach between Section 3 and
Section 4. Please change the "n"
value of the internal bridge
opening section or provide
supporting information for the
use of a higher "n" value.
253.335(Bridge-UP)
NT TL 01S2 This is Section2 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively, for typical
structure sections according to
page 5-8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010).
253.33
NT TL 01S3 This is Section3 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively, for typical
structure sections according to
page 5-8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010).
253.35
NT TL 01S4 This is Section 4 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively according to page 5-
8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010)..
253.4
ST DT 03 This is ($Structure$) section.
The Contraction Length is longer
than the Expansion Length.
Section 4 channel distance of
$Length_Chnl4$ is longer than
Section 2 channel distance of
$Length_Chnl2$.
Section 4 and Section 1 should be
relocated.
The HEC-RAS geometry file may
need to be recreated using a GIS
program.
253.335(Bridge-UP)
ST IF 04S2R This is Section 2.
The selected profile is
$profilename$.
Weir flow occurs at
($strucname$).
However, the right ineffective
flow elevation of $ineffell$ at
the right ineffective flow
station $ineffstar$ is equal to
or higher than the WSEL of
$wsel2$. The upstream RMnTpRu is
$rmntprdu$. The ineffective flow
elevation should be lower than
the WSEL at Section 2.
253.33(Bridge)
ST IF 04S3R This is Section 3.
The selected profile is
$profilename$.
Weir flow occurs at
($strucname$).
However, the right ineffective
flow elevation of $ineffell$ at
the right ineffective flow
station $ineffstar$ is equal to
or higher than the WSEL of
$wsel3$. The computed upstream
RMnTpRd is $rmntprdu$. The
ineffective flow elevation should
be equal to the computed
RMnTpRdU.
253.35(Bridge)
ST IF 05S2R This is Section 2 of a hydraulic
structure.
The right ineffective flow
station is within the opening
area of the structure.
The right ineffective flow
station of $ineffstar$ is less
than the upstream right abutment
station of $abutstar$ at
($strucname$). The Right
ineffective flow station should
be adjusted.
253.33(Bridge)
ST IF 05S3R This is Section 3 of a hydraulic
structure.
The right ineffective flow
station is within the opening
area of the structure.
The right ineffective flow
station of $ineffstar$ is less
than the upstream right abutment
station of $abutstar$ at
($strucname$). The Right
ineffective flow station should
be adjusted.
253.35(Bridge)
ST IF 07S1R This is Section 1.
Right Ineffective flow option was
considered at this section.
However, it should be a fully
expanded cross section.
Ineffective flow stations and
elevations should be cleared from
this section, unless the areas
beyond the ineffective flow
stations
are not within the flow path of
the stream.
This message should be ignored if
this section is Section 3 of the
downstream structure.
253.32(Bridge)
ST IF 07S4R This is Section 4.
Right Ineffective flow option was
considered at this section.
However, it should be a fully
expanded cross section.
Ineffective flow stations and
elevations should be cleared from
this section, unless the areas
beyond the ineffective flow
stations
are not within the flow path of
the stream.
This message should be ignored if
this section is Section 2 of the
upstream structure.
253.4(Bridge)
XS IF 03R The Right Ineffective Flow
Station is within the channel.
The Right Ineffective Flow
Station of $ineffstar$ is less
than the RightBankSta of
$bankstar$. The Right Ineffective
Flow Station or the RightBankSta
should be adjusted.
253.33; 253.35
XS SW 01DK The name of the stream is
$streamname$.
The flow regime is subcritical or
mixed flow.
Starting WSEL is computed from
Known WSEL as the downstream
boundary
for $Assigned_Name$ flood.
Provide backup information on
Known WSEL or use energy slope as
the
downstream boundary.
251.79
cHECk-RAS Report
HEC-RAS Project:wrnproposed.prj
Plan File:wrnproposed.p05
Geometry File:wrnproposed.g03
Flow File:wrnproposed.f03
Report Date:4/24/2025
Message ID Message Cross sections affected Comments
MP SW 01DK The name of the stream is
($streamname$).
The flow regime is subcritical or
mixed flow.
Starting water-surface elevations
are computed from Known WSELs as
the downstream boundary
condition.
Provide backup information on
Known water-surface elevations or
use same energy slope for all the
profiles as the starting boundary
condition and rerun the plan.
NT RS 02BDC This is the Downstream Bridge
Section (BRD). The channel n
value of $chldn$ for the
downstream internal bridge
opening section is equal to or
larger than the channel n value
of $chl2$ at Section 2. Usually,
the channel "n" value of the
bridge opening section represents
the area below the bridge deck
and is less than the channel "n"
value of Section 2. The "n" value
for Section 2 represents the
natural valley channel section
roughness for the reach between
Section 3 and Section 4. Please
change the "n" value of the
internal bridge opening section
or provide supporting information
for the use of the higher "n"
value.
253.335(Bridge-DN)
NT RS 02BUC This is the Upstream Bridge
Section (BRU). The channel n
value of $chlup$ for the upstream
internal bridge opening section
is equal to or larger than the
channel n value of $chl3$ at
Section 3. Usually, the channel
"n" value of the bridge opening
section represents the area below
the bridge deck and is less than
the channel "n" value of Section
3.
The "n" value for Section 3
represents the natural valley
channel section roughness for the
reach between Section 3 and
Section 4. Please change the "n"
value of the internal bridge
opening section or provide
supporting information for the
use of a higher "n" value.
253.335(Bridge-UP)
NT TL 01S2 This is Section2 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively, for typical
structure sections according to
page 5-8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010).
253.33
NT TL 01S3 This is Section3 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively, for typical
structure sections according to
page 5-8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010).
253.35
NT TL 01S4 This is Section 4 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively according to page 5-
8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010)..
253.4
ST DT 03 This is ($Structure$) section.
The Contraction Length is longer
than the Expansion Length.
Section 4 channel distance of
$Length_Chnl4$ is longer than
Section 2 channel distance of
$Length_Chnl2$.
Section 4 and Section 1 should be
relocated.
The HEC-RAS geometry file may
need to be recreated using a GIS
program.
253.335(Bridge-UP)
ST IF 04S2R This is Section 2.
The selected profile is
$profilename$.
Weir flow occurs at
($strucname$).
However, the right ineffective
flow elevation of $ineffell$ at
the right ineffective flow
station $ineffstar$ is equal to
or higher than the WSEL of
$wsel2$. The upstream RMnTpRu is
$rmntprdu$. The ineffective flow
elevation should be lower than
the WSEL at Section 2.
253.33(Bridge)
ST IF 04S3R This is Section 3.
The selected profile is
$profilename$.
Weir flow occurs at
($strucname$).
However, the right ineffective
flow elevation of $ineffell$ at
the right ineffective flow
station $ineffstar$ is equal to
or higher than the WSEL of
$wsel3$. The computed upstream
RMnTpRd is $rmntprdu$. The
ineffective flow elevation should
be equal to the computed
RMnTpRdU.
253.35(Bridge)
ST IF 05S2R This is Section 2 of a hydraulic
structure.
The right ineffective flow
station is within the opening
area of the structure.
The right ineffective flow
station of $ineffstar$ is less
than the upstream right abutment
station of $abutstar$ at
($strucname$). The Right
ineffective flow station should
be adjusted.
253.33(Bridge)
ST IF 05S3R This is Section 3 of a hydraulic
structure.
The right ineffective flow
station is within the opening
area of the structure.
The right ineffective flow
station of $ineffstar$ is less
than the upstream right abutment
station of $abutstar$ at
($strucname$). The Right
ineffective flow station should
be adjusted.
253.35(Bridge)
ST IF 07S1R This is Section 1.
Right Ineffective flow option was
considered at this section.
However, it should be a fully
expanded cross section.
Ineffective flow stations and
elevations should be cleared from
this section, unless the areas
beyond the ineffective flow
stations
are not within the flow path of
the stream.
This message should be ignored if
this section is Section 3 of the
downstream structure.
253.32(Bridge)
ST IF 07S4R This is Section 4.
Right Ineffective flow option was
considered at this section.
However, it should be a fully
expanded cross section.
Ineffective flow stations and
elevations should be cleared from
this section, unless the areas
beyond the ineffective flow
stations
are not within the flow path of
the stream.
This message should be ignored if
this section is Section 2 of the
upstream structure.
253.4(Bridge)
XS IF 03R The Right Ineffective Flow
Station is within the channel.
The Right Ineffective Flow
Station of $ineffstar$ is less
than the RightBankSta of
$bankstar$. The Right Ineffective
Flow Station or the RightBankSta
should be adjusted.
253.33; 253.35
XS SW 01DK The name of the stream is
$streamname$.
The flow regime is subcritical or
mixed flow.
Starting WSEL is computed from
Known WSEL as the downstream
boundary
for $Assigned_Name$ flood.
Provide backup information on
Known WSEL or use energy slope as
the
downstream boundary.
251.79
cHECk-RAS Report
HEC-RAS Project:wrndupeff.prj
Plan File:wrndupeff.p01
Geometry File:wrndupeff.g17
Flow File:wrndupeff.f02
Report Date:4/24/2025
Message ID Message Cross sections affected Comments
MP SW 01DK The name of the stream is
($streamname$).
The flow regime is subcritical or
mixed flow.
Starting water-surface elevations
are computed from Known WSELs as
the downstream boundary
condition.
Provide backup information on
Known water-surface elevations or
use same energy slope for all the
profiles as the starting boundary
condition and rerun the plan.
NT RS 02BDC This is the Downstream Bridge
Section (BRD). The channel n
value of $chldn$ for the
downstream internal bridge
opening section is equal to or
larger than the channel n value
of $chl2$ at Section 2. Usually,
the channel "n" value of the
bridge opening section represents
the area below the bridge deck
and is less than the channel "n"
value of Section 2. The "n" value
for Section 2 represents the
natural valley channel section
roughness for the reach between
Section 3 and Section 4. Please
change the "n" value of the
internal bridge opening section
or provide supporting information
for the use of the higher "n"
value.
253.335(Bridge-DN)
NT RS 02BUC This is the Upstream Bridge
Section (BRU). The channel n
value of $chlup$ for the upstream
internal bridge opening section
is equal to or larger than the
channel n value of $chl3$ at
Section 3. Usually, the channel
"n" value of the bridge opening
section represents the area below
the bridge deck and is less than
the channel "n" value of Section
3.
The "n" value for Section 3
represents the natural valley
channel section roughness for the
reach between Section 3 and
Section 4. Please change the "n"
value of the internal bridge
opening section or provide
supporting information for the
use of a higher "n" value.
253.335(Bridge-UP)
NT TL 01S2 This is Section2 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively, for typical
structure sections according to
page 5-8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010).
253.33
NT TL 01S3 This is Section3 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively, for typical
structure sections according to
page 5-8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010).
253.35
NT TL 01S4 This is Section 4 of a hydraulic
structure. The contraction and
expansion loss coefficients are
$cc$ and $ce$. They should be
equal to 0.3 and 0.5,
respectively according to page 5-
8 of the HEC-RAS Hydraulic
Reference Manual (HEC, 2010)..
253.4
ST DT 03 This is ($Structure$) section.
The Contraction Length is longer
than the Expansion Length.
Section 4 channel distance of
$Length_Chnl4$ is longer than
Section 2 channel distance of
$Length_Chnl2$.
Section 4 and Section 1 should be
relocated.
The HEC-RAS geometry file may
need to be recreated using a GIS
program.
253.335(Bridge-UP)
ST IF 04S2R This is Section 2.
The selected profile is
$profilename$.
Weir flow occurs at
($strucname$).
However, the right ineffective
flow elevation of $ineffell$ at
the right ineffective flow
station $ineffstar$ is equal to
or higher than the WSEL of
$wsel2$. The upstream RMnTpRu is
$rmntprdu$. The ineffective flow
elevation should be lower than
the WSEL at Section 2.
253.33(Bridge)
ST IF 04S3R This is Section 3.
The selected profile is
$profilename$.
Weir flow occurs at
($strucname$).
However, the right ineffective
flow elevation of $ineffell$ at
the right ineffective flow
station $ineffstar$ is equal to
or higher than the WSEL of
$wsel3$. The computed upstream
RMnTpRd is $rmntprdu$. The
ineffective flow elevation should
be equal to the computed
RMnTpRdU.
253.35(Bridge)
ST IF 05S2R This is Section 2 of a hydraulic
structure.
The right ineffective flow
station is within the opening
area of the structure.
The right ineffective flow
station of $ineffstar$ is less
than the upstream right abutment
station of $abutstar$ at
($strucname$). The Right
ineffective flow station should
be adjusted.
253.33(Bridge)
ST IF 05S3R This is Section 3 of a hydraulic
structure.
The right ineffective flow
station is within the opening
area of the structure.
The right ineffective flow
station of $ineffstar$ is less
than the upstream right abutment
station of $abutstar$ at
($strucname$). The Right
ineffective flow station should
be adjusted.
253.35(Bridge)
ST IF 07S1R This is Section 1.
Right Ineffective flow option was
considered at this section.
However, it should be a fully
expanded cross section.
Ineffective flow stations and
elevations should be cleared from
this section, unless the areas
beyond the ineffective flow
stations
are not within the flow path of
the stream.
This message should be ignored if
this section is Section 3 of the
downstream structure.
253.32(Bridge)
ST IF 07S4R This is Section 4.
Right Ineffective flow option was
considered at this section.
However, it should be a fully
expanded cross section.
Ineffective flow stations and
elevations should be cleared from
this section, unless the areas
beyond the ineffective flow
stations
are not within the flow path of
the stream.
This message should be ignored if
this section is Section 2 of the
upstream structure.
253.4(Bridge)
XS IF 03R The Right Ineffective Flow
Station is within the channel.
The Right Ineffective Flow
Station of $ineffstar$ is less
than the RightBankSta of
$bankstar$. The Right Ineffective
Flow Station or the RightBankSta
should be adjusted.
253.33; 253.35
XS SW 01DK The name of the stream is
$streamname$.
The flow regime is subcritical or
mixed flow.
Starting WSEL is computed from
Known WSEL as the downstream
boundary
for $Assigned_Name$ flood.
Provide backup information on
Known WSEL or use energy slope as
the
downstream boundary.
251.79
APPENDIX E
Comparative Cross Section Plots
Citizens Energy Group
White River North Water Treatment Plant Expansion
WRN WTP Expansion Floodplain Model
WRN Expansion Existing vs
Proposed Model Results
Comparison
Existing
Proposed
Comparison
Profile